Fetal scalp blood sampling during second stage of labor – analyzing lactate or pH? A secondary analysis of a randomized controlled trial
Open Access
- 19 March 2020
- journal article
- research article
- Published by Taylor & Francis Ltd in The Journal of Maternal-Fetal & Neonatal Medicine
- Vol. 35 (6), 1100-1107
- https://doi.org/10.1080/14767058.2020.1743656
Abstract
Background: Cardiotocography (CTG) is a widely used method for assessing fetal wellbeing during labor. It is well-known that CTG has high sensitivity but low specificity. To avoid unnecessary operative interventions, adjunctive methods such as fetal blood sampling (FBS) are used. Few studies have looked into whether FBS can be used during second stage of labor, and in that case, which of the methods (lactate or pH) are preferred. Objective: To evaluate clinical effectiveness of measuring lactate versus pH in preventing birth acidemia when FBS was performed during second stage of labor. Methods: Secondary analysis of a randomized controlled trial . Thousand three hundred and thirty-eight women with a singleton pregnancy, cephalic presentation, gestational age ≥34 weeks, and indication for FBS during second stage of labor were included. Main outcome measures: Metabolic acidemia (pH 12 mmol/l) or pH < 7.00 in cord arterial blood at birth. Secondary outcomes: A composite outcome (metabolic acidemia, pH <7 or Apgar score <4), and rates of operative deliveries. Results: Metabolic acidemia occurred in 4.1% in the lactate versus 5.1% in the pH group (relative risk (RR): 0.80; 95% confidence interval (CI): 0.48–1.35) and pH <7 in 1.4% versus 2.8% (RR: 0.51, 95% CI: 0.23–1.13). Composite outcome was found in 3.8 versus 4.9%, respectively (RR: 0.76; 95% CI: 0.46–1.26). No difference in total operative interventions was found. More cesarean deliveries were performed in the lactate group (16.5 vs. 12.4%; RR: 1.33; 95% CI: 1.02–1.74). Conclusion: When analyzing lactate or pH in fetal scalp blood during second stage of labor neonatal outcomes were comparable. The frequency of total operative interventions was similar but more cesarean deliveries were performed in the lactate group.Keywords
Funding Information
- This study was financially supported by Signhild-Engqvists-Stiftelse
- FOU-Västra Götaland
This publication has 24 references indexed in Scilit:
- Intrapartum fetal scalp lactate sampling for fetal assessment in the presence of a non-reassuring fetal heart rate traceEmergencias, 2015
- Fetal scalp blood sampling during labor: an appraisal of the physiological basis and scientific evidenceActa Obstetricia et Gynecologica Scandinavica, 2014
- Fetal scalp blood sampling in labor – a reviewActa Obstetricia et Gynecologica Scandinavica, 2014
- Comparing fetal scalp lactate and umbilical cord arterial blood gas valuesAustralian and New Zealand Journal of Obstetrics and Gynaecology, 2014
- Is intrapartum fetal blood sampling a gold standard diagnostic tool for fetal distress?European Journal of Obstetrics & Gynecology and Reproductive Biology, 2011
- Fetal Scalp Lactate Microsampling for Non-Reassuring Fetal Status during Labor: A Prospective Observational StudyFetal Diagnosis and Therapy, 2009
- Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trialBMJ, 2008
- Base deficit estimation in umbilical cord blood is influenced by gestational age, choice of fetal fluid compartment, and algorithm for calculationAmerican Journal of Obstetrics and Gynecology, 2006
- Scalp blood lactate: a new test strip method for monitoring fetal wellbeing in labourBJOG: An International Journal of Obstetrics and Gynaecology, 1995